Products

Low Heat Concrete CPAC

Details
Reduce problems and concerns about concrete cracking due to temperature (Thermal Crack) with special concrete that is designed to generate lower heat than normal concrete, especially for structures that are thicker than 50 cm.

Because in general, concrete will release heat after the cement in the concrete reacts with water, especially for structures that are thicker than 50 cm. The heat that accumulates inside the structure may be higher than 70 degrees Celsius, causing a difference between the temperature on the surface and the temperature inside the structure (Differential Temperature), causing the concrete to shrink and adhere differently. Eventually, the concrete will crack (Thermal Crack), causing water and moisture to seep through the concrete structure to destroy the reinforcing steel, causing the structure to be unable to support the weight as designed.

Suitable for work types
Structures that are thicker than 50 cm., such as large foundations, large beams, concrete dams

Properties
It is a concrete that is designed to release less heat than normal concrete.
The concrete texture is smooth, easy to pour, easy to shake, helping to reduce working time.
The long-term compressive strength is higher than normal concrete, with low water retention, separation and shrinkage.
Recommendations for use and precautions
The side form should be a wooden form. Because it has good thermal insulation value, the concrete should be cured after pouring with insulation, such as foam or dry sand, about 5 cm thick, to make the temperature in the structure similar.
For large foundations that are divided into horizontal layers, the upper reinforcing steel should be taken into account between the poured layers to prevent cracking of the concrete on the upper surface (please consider according to the ACI 207.2R standard).
Dividing large foundations Vertical division - must insert reinforcing steel (Dowel) to receive vertical shear force at the joints of the concrete.
Horizontal division - must insert reinforcing steel (Dowel) to receive horizontal shear force at the joints of the concrete layers, including adding reinforcing steel to prevent cracking on the upper surface of the lower concrete layer.
Insulation Cure Method Curing concrete with insulation to control the temperature on the surface from being transferred too quickly, causing a difference between the internal and external temperatures, causing different shrinkage and leading to cracking.
The method of insulation curing is as follows:
- Cover with plastic sheets, with the joints of the plastic sheets Overlap and leave a distance of not less than 15 cm.

- Place foam with a thickness of at least 2 cm. on the plastic sheet.

- Cover again with a plastic sheet, with the joints of the plastic sheets overlapping and leaving a distance of not less than 15 cm.

- Find materials to cover to prevent the plastic sheet from flying.

In the case of installing a concrete thermometer in the structure, the time to remove the insulation can be considered by waiting until the concrete temperature at the core drops to a level that does not cause cracking (the difference between the temperature at the core of the concrete and the air temperature must be less than 35 degrees Celsius).